gzt: Try looking in HKEY_CLASSES_ROOT for the HTTP handler and compare that to a known good machine.

Actually, this key is built per user logon.

Log on as a different user.

If IE works correctly for the new user then we can think about which key to export.

As a result of a later prompt I tried this. Opening a url from a WORD doc does not work under the existing userid but does work from the new userid. Looking at HKEY_CLASSES_ROOT\http the various entries are identical for both users.

Time to examine: HKEY_CURRENT_USER\Software\Classes\http\shell\open\ for each user.

Under the new user there are virtually no keys under the above directory, however under the existing user there are a number of entries such as .htm, .html etc (note the preceeding dot and no http key) all of which have a default of "ChromeHTML". Looks like paydirt here because Chrome is not installed AFAIK. Is it safe to delete all the entries that show a value of"ChromeHTML"?

Time to examine: HKEY_CURRENT_USER\Software\Classes\http\shell\open\ for each user.

Under the new user there are virtually no keys under the above directory, however under the existing user there are a number of entries such as .htm, .html etc (note the preceeding dot and no http key) all of which have a default of "ChromeHTML". Looks like paydirt here because Chrome is not installed AFAIK. Is it safe to delete all the entries that show a value of"ChromeHTML"?

I would strongly suggest just nuking the key entirely and importing from your "fresh" user. Take backup first!

+1. It can take a lot of persistence and fortitude to track down the solution to this kind of problem!

My big concern here is what this says about Google's software. That's two of us in this thread who have suffered malfunctions and lost many hours finding a fix after installing and uninstalling Chrome! Surely a well written uninstaller should restore the registry to the condition it was in beforehand? It seems like Google are arrogant enough to assume that Chrome is so amazingly wonderful that no-one would dream of removing it? And it bugs me the way Chrome gets pushed out with updates and downloads of so munch other un-related software by default. Very annoying...

colinuu: Surely a well written uninstaller should restore the registry to the condition it was in beforehand?

Short answer - Yes. Long answer - Sometimes applications call Windows functions to register and unregister things in the registry and Windows does not work as advertised. This is not uncommon and there are all sorts of additional code required to cater for those situations in a custom way. Likely the current installer code does not know about these things.

colinuu: It seems like Google are arrogant enough to assume that Chrome is so amazingly wonderful that no-one would dream of removing it?

Chrome can be installed/removed both in the current user context and in the system context. Very likely Google has not thought through every combination of that. There are open issues in that area.

A large portion of the Chrome browser is open source. I have not checked to see if the installer is open source, but it probably is - because the project does accept reports on the Chrome install/uninstall.

I can see someone has reported things left behind in the registry after uninstall - but the true impact of the problem in the way that it affected OldGeek has not been reported.

If you liked Chrome you might report the issues - but then if you don't like it and then uninstall it and then suffer from this issue - then you are unlikely to want to spend any time reporting at all. ; ).

Quick summary: Yes this part of uninstall could be better. Google and/or the project should look at this.

If Google wants to donate me a Windows machine I'd be happy to take a good look at what is going on in this area.

I spoke too soon, the problem has returned. The registry does not contain the deleted keys so I have no reason to believe that it has been restored from a backup by some automated process.

A search of the registry for chromehtml reveals 11 references - 1 in KKEY_CLASSES_ROOT\chromehtml, 4 in HKEY_CURRENT_USER\software\Microsoft\windows\CurrentVersion\Explorer\FileExts, 2 in HKEY_LOCAL_MACHINE\software\classes and 4 in HKEY_USERS\S-1-5-21-1315360783-1704792791-3995418313-1000\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts

My inclination is to delete these keys as they reference chrome. However I thought I would check here first because of the Explorer references.

It is built for each user within each user session at logon based on the user details stored in hkey_users for each user - i.e; HKEY_USERS\S-1-5-21-1315360783-1704792791-3995418313-1000 is a user.

Terminology: In the registry a 'folder' item is called a key. The items stored in that folder are called value/data pairs, or just a 'value'.

OldGeek: My inclination is to delete these keys as they reference chrome.

I'm not exactly sure if you are talking about deleting a key or a value. Deleting all the 'keys' you specified wholesale would be a very bad idea.

Deleting 'values' that reference Chrome should be ok and have no impact on the rest of the system.

Deleting 'keys' that are clearly origin from Chrome is fine also.

Deleting entire 'keys' that contain Chrome values but also contain values related to other applications may cause problems.

HKEY_CURRENT_USER\software\Microsoft\windows\CurrentVersion\Explorer\FileExts stores values personal to the users login session and can be viewed and edited in control panel > default programs > file associations. Manually deleting chrome 'values' from that key should be fine.

Manually deleting chrome values and keys from HKEY_LOCAL_MACHINE\software\classes is a good idea.

HKEY_USERS\S-1-5-21-1315360783-1704792791-3995418313-1000\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts is probably the user you are currently logged in as and the one from which current user was built. Just guessing, it could be any other user.

There's a gotcha here you should be aware of. Updating the registry manually does not automatically update Windows running environment with the latest settings. There are things Windows only learns about and updates the current environment on logon and logoff and some things on start. There are a fair few things you can force an update for by endtasking explorer.exe, then starting it again if needed.

But really, to fully see the effects of your changes - a restart is the best idea.